President Barack Obama has stressed that the U.S.-led coalition fight against the Islamic State can be won without “boots on the ground.” But it depends on who’s wearing the boots.

Thousands of private security contractors, who played critical, below-the-radar and at times controversial roles in the wars in Iraq and Afghanistan, are being asked to consider joining this latest battle against Islamic extremists in Iraq and Syria and possibly elsewhere in the Middle East. What specific jobs they will fill, and which departments or countries will be paying for their services, remains to be seen. But the demand for their considerable and varied expertise is expected to be high, and that’s welcome news for both the contracting companies and politicians, according to policy advisers and industry experts.

“I think Obama’s promise not to send ground troops to Iraq and Syria, combined with the threat there, incentivizes the administration to turn to contractors because there are such fewer political risks,” says George Washington University law professor Laura A. Dickinson, author of “Outsourcing War and Peace: Preserving Public Values in a World of Privatized Foreign Affairs.”

“Private security contractors can’t engage in combat, but they can oversee training and logistics and can provide security,” Dickinson says. “I recently saw a posting looking for companies interested in constructing a network of satellite stations. So there will be many opportunities to be involved.”

And that’s a good thing for a private industry that has watched with dismay over the last couple of years as the U.S. government has extricated itself from Iraq and, soon, Afghanistan.

“The private-sector industry views ISIS as a potential marketplace,” says Sean McFate, a professor at the National Defense University and Georgetown University’s School of Foreign Service and author of “The Modern Mercenary: Private Armies and What They Mean for World Order.” “My guess would be that private contractors are eagerly wandering the halls of K Street and Pentagon City, offering their services. There’s blood in the water.”

During the height of the U.S. military “surge” in Iraq in 2007, more than 180,000 private contractors were stationed throughout the region, according to Peter Singer, a military strategist and senior fellow at the New America Foundation.

“It was greater than a 1:1 ratio to U.S. forces — a lot like parallel troops,” Singer says. “The number goes down as U.S. forces shrink, but the bottom line is they didn’t go away. They’ve just shifted to different roles — from analysts to translators and security guards to training the Iraqi Air Force.”

Training and equipping foreign forces in Syria is a key component of the administration’s plan to defeat ISIS, and signs already point to a plan that involves at least a partial reliance on private security firms to assist — and not just in Syria.

“We’re seeing the framework be put into place,” Singer says. “In August, the U.S. Army Contracting Command posted a notice for contractors willing to work an initial 12-month contract that will focus on force-development operations. They posted one of these before the 2003 invasion (of Iraq), and Halliburton expressed interest.”

In its expansive announcement for “Security Assistance Mentors and Advisors” in Iraq, the Army says it is looking for contractors to help the Baghdad government, “cognizant of the goals of reducing tensions between Arabs and Kurds, and Sunni and Shias, with key focus on core process and systems which involve, but are not limited to administration, force development, procurement and acquisition, contracting, training management, public affairs, logistics, personnel management, professional development, communications, planning and operations, infrastructure management, intelligence and executive development.”

Those interested had until Aug. 25 to respond. A formal call for applicants has not yet gone out. But McFate, a former U.S. Army officer and later a program manager for powerhouse military contractor DynCorp International in Africa, says the turnaround could be quick.

“Many of these companies have been pre-vetted and can be deployed very quickly,” he says. “In fact, many are already doing work for either State or DOD in some capacity.”

In July, the State Department renewed a no-bid contract with defense contractor Triple Canopy, doubling the number of guards providing security to the U.S. consulate in the Kurdish capital of Erbil, Iraq.

Back in 2010, McFate’s former employer, Dyncorp, signed a five-year deal worth up to roughly $900 million to provide a fleet of aircraft, including UH-1 “Huey” utility helicopters and Bombardier Dash 8 turboprop airliners.

Of the $4 billion allocated to the State Department for Afghanistan reconstruction from 2002 to 2013, DynCorp received 69 percent, or nearly $3 billion, according to the Special Inspector General for Afghanistan Reconstruction.

With the political gain of avoiding public outcry over U.S. ground troops being deployed back to the region comes the political risk of relying on a private military that has had instances of misconduct.

When these companies end up in the spotlight, it’s often because something has gone wrong. The most well-known private military contracting firm no longer exists: Blackwater Worldwide, founded by charismatic and controversial former Navy SEAL Erik Prince, has undergone several name changes and leadership shake-ups since four security guards were accused of killing 14 Iraqis in Baghdad in 2007.

Two years after the shooting, the North Carolina-based Blackwater renamed itself Xe Services LLC. In 2010, Prince left the company, selling his stake to investor group USTC Holdings LLC and moving to Abu Dhabi, where he has been linked to efforts to build a mercenary force for the United Arab Emirates, a critical ally in the U.S.-led coalition against ISIS.

The following year, Xe Services morphed again, calling itself Academi. And this summer, the private security company joined forces with rival firm Triple Canopy to form Constellis Holdings.

The consolidation brings more than 6,000 employees under one umbrella, which includes a new board of directors made up of Washington insiders: John Ashcroft, who was President George W. Bush’s attorney general for five years; Jack Quinn, a counsel to President Bill Clinton and Vice President Al Gore; and retired Adm. Bobby Inman, former director of the National Security Agency and deputy CIA director.

The State Department has worked frequently with Triple Canopy to protect its embassies and consulates around the world. In 2012, the firm received more than $200 million in contracts for the security of the U.S. Embassy in Baghdad. The next year it received $5 million more to protect the U.S. Consulate in Basra, Iraq.

But it is the reliance on these same players that has raised red flags for critics, including high-profile lawmakers such as Senate Judiciary Committee Chairman Patrick J. Leahy.

Law professor Dickinson says that the big concern is, “have we really learned our lessons from the last round of wars where we witnessed colossal failures, huge problems with waste, misconduct and transparency?”

In July, Leahy re-introduced legislation to allow the Justice Department to prosecute non-Defense Department contractors and government employees for some crimes committed overseas.

The bill would close a potential gap in the federal government’s jurisdiction over civilian contractors.

Another move toward greater accountability, according to Dickinson, is a voluntary agreement led by the Swiss government called the International Code of Conduct (ICoC ) for private security service providers.

“There’s wide support for that code with hundreds of companies (including DynCorp, Triple Canopy and Academi) signing on, although it remains to be seen how it will be enforced,” she says

In August, the State Department said it anticipated making membership in the ICoC Association a requirement for companies bidding for security contracts.

While contractor misconduct presents short-term risks, McFate and others warn about the potential long-term damage of sub-contractors and sub-sub-contractors who will remain far outside U.S. jurisdiction.

“One facet of these industries maturing and becoming billion-dollar behemoths is that they’re starting to go indigenous,” McFate says.

“The leading firms are going into Iraq and Afghanistan and hiring lots of local personnel and then those guys are hiring their brother the warlord,” he explains. “When the primary contractor leaves, the subcontractor may not want to go out of business. Why not keep working with the political parties or warlords or become your own warlord?”

At this point, the political cover outweighs these and other concerns, McFate says.

“Using contractors is a tricky choice and there are some long term risks. But it sends a different type of message — it’s less political. When most Iraqis think of contractors, they don’t have warm and fuzzy feelings,” he says. “But sending in U.S. troops? It’s a different signal. One of Osama bin Laden’s main grievances was foreign troops inside the kingdom.”

Singer has a simpler explanation: “For whatever reason, Americans don’t get as upset when a contractor gets killed.”